UL 19G:2018-08 Guidance for Lined Fire Hose and Hose Assemblies.
1.1 This document is to inform users of fire hose and UL 19, Lined Fire Hose and Hose Assemblies, the intent behind the test results from the radiant heat test and conductive heat test. This includes the history of the method development and the final choice of parameters used in the test methods.
1.2 It is important to note that the results from the radiant heat test and conductive heat test represent a specific set of test parameters that are not intended to represent the dynamic fire environment.
2 Radiant Heat and Conductive Heat Test Results
Note — The language found in UL 19G is a duplicate of the language in UL 19, Appendix C.
2.1 The results reported in terms of time to pressure loss and leakage rate relate only to the specific set of parameters used for testing. These values can only be used to compare new hose performance against one another under the specific test conditions in the method. The results are not intended to represent actual hose performance in the fire environment, which is continually changing. Hoses may perform differently under several conditions including, higher or lower heat fluxes, higher or lower temperatures, higher or lower pressures, age of hose, wear of hose, if hose is wet or dry, charged or uncharged, and other fire environment variables. In addition it should also be noted that these test methods utilize a small section of hose and not a complete hose that may be stretched out through a fire environment. All of the aforementioned factors have the potential to change both the time to pressure loss and leakage rate. As such, the results reported in this section are intended to be used as a baseline for comparative purposes only and not assumed performance in the field.
The results reported for these tests contain the following:
• Radiant heat exposure of 30 kw/m2 — this represents the static heat flux used for the test
• Conductive heat exposure with steel block at 400°C (752°F) — this represents the temperature
of the steel block upon removal from the oven and placement on the hose for this test method
• Exposure duration — this represents the time to a 20 psi pressure loss in the static pressurized
sample being tested
• Average leakage rate — This represents the average leakage rate of the samples specified for
post exposure testing when charged at 150 psi
• Maximum leakage rate — This represents the maximum leakage rate of the samples specified
for post exposure testing when charged at 150 psi
Following the exposure, the sample leakage rate is determined by charging the sample with water at 150 psi. During the development phase of the Radiant Test and Conductive test procedures, it was observed that current hose constructions exhibited a wide range of failure modes, which ranged from a gradual weeping or slightly leaking condition, to a more violent, sudden burst-like failure mode. It was also noted that the weeping or leaking type of failure may introduce a self-protecting feature. In effort to characterize these differences in failure, the post exposure leakage rate was added as a second stage of the test methods. Observations from sample testing indicated that the burst type failures generally had higher leakage rates.UL 19G pdf download.